From 4b51819d4ca525a8b68ddc3e3541c1bfcfc5a28c Mon Sep 17 00:00:00 2001
From: Will Handley <wh260@cam.ac.uk>
Date: Mon, 5 Nov 2018 19:26:55 +0000
Subject: [PATCH] Added reverse script

---
 README.rst | 22 ++++++++++++----------
 example.py |  7 +++++--
 nb2py      | 44 ++++++++++++++++++++++++++++++++++++++++++++
 setup.py   |  2 +-
 4 files changed, 62 insertions(+), 13 deletions(-)
 create mode 100755 nb2py

diff --git a/README.rst b/README.rst
index d49c37b..d179aaa 100644
--- a/README.rst
+++ b/README.rst
@@ -3,7 +3,7 @@ py2nb: convert python scripts to jupyter notebooks
 ==================================================
 :py2nb: convert python scripts to jupyter notebooks
 :Author: Will Handley
-:Version: 0.0.3
+:Version: 0.0.4
 :Homepage: https://github.com/williamjameshandley/py2nb
 
 .. image:: https://badge.fury.io/py/py2nb.svg
@@ -19,6 +19,8 @@ markdown to jupyter notebooks.
 Markdown cells are rendered from comments beginning with ``#|``, splits between
 code cells are created by comment lines beginning with ``#-``
 
+``nb2py`` converts from jupyter notebooks to python
+
 Installation
 ============
 
@@ -52,26 +54,28 @@ If one has a script named ``example.py`` containing the code:
    #| a jupyter notebook with a simple additional markdown format.
    #|
    #| Code by default will be put into code cells
-   #| 
+   #|
    #| * To make a markdown cell, prefix the comment line with with '#|'
    #| * To split a code cell, add a line beginning with '#-'
-
+   
    import numpy
    import matplotlib.pyplot as plt
    %matplotlib inline
-
+   
    #| Here is a markdown cell.
    #| Maths is also possible: $A=B$
    #|
    #| There are code cells below, split by '#-':
-
+   
    x = numpy.random.rand(5)
-   #---------------------------
+   
+   #-------------------------------
+   
    y = numpy.random.rand(4)
    z = numpy.random.rand(3)
-
+   
    #| Here are some plots
-
+   
    x = numpy.linspace(-2,2,1000)
    y = x**3
    fig, ax = plt.subplots()
@@ -82,12 +86,10 @@ then running
 .. code :: bash
    
    py2nb example.py
-
    
 produces the notebook `example.ipynb <https://github.com/williamjameshandley/py2nb/blob/master/example.ipynb>`_
 
 To do
 =====
-- reverse script
 - evaluation option for script produced
 - vim syntax highlighting for markdown code blocks
diff --git a/example.py b/example.py
index 2d98736..fc3a9a3 100644
--- a/example.py
+++ b/example.py
@@ -3,7 +3,7 @@
 #| a jupyter notebook with a simple additional markdown format.
 #|
 #| Code by default will be put into code cells
-#| 
+#|
 #| * To make a markdown cell, prefix the comment line with with '#|'
 #| * To split a code cell, add a line beginning with '#-'
 
@@ -17,7 +17,9 @@
 #| There are code cells below, split by '#-':
 
 x = numpy.random.rand(5)
-#---------------------------
+
+#-------------------------------
+
 y = numpy.random.rand(4)
 z = numpy.random.rand(3)
 
@@ -27,3 +29,4 @@
 y = x**3
 fig, ax = plt.subplots()
 ax.plot(x,y)
+
diff --git a/nb2py b/nb2py
new file mode 100755
index 0000000..38b7720
--- /dev/null
+++ b/nb2py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+"""Create a notebook containing code from a script.
+
+Run as:  python to_noteebook.py my_script.py
+"""
+import os
+import argparse
+import json
+
+
+def convert(notebook_name):
+    """ Convert the jupyter notebook to python script"""
+    script_name = os.path.splitext(notebook_name)[0] + '.py'
+    with open(notebook_name, 'r') as f_in:
+        with open(script_name, 'w') as f_out:
+            last_source = ''
+            f_in = json.load(f_in)
+            for cell in f_in['cells']:
+                if last_source == 'code' and cell['cell_type'] == 'code':
+                    f_out.write('#-------------------------------\n\n')
+                for line in cell['source']:
+                    if cell['cell_type'] == 'markdown':
+                        line = '#| ' + line.lstrip()
+                    line = line.rstrip() + '\n'
+                    f_out.write(line)
+                f_out.write('\n')
+                last_source = cell['cell_type']
+
+
+def parse_args():
+    """Argument parsing for py2nb"""
+    description = "Convert a python script to a jupyter notebook"
+    parser = argparse.ArgumentParser(description=description)
+    parser.add_argument("notebook_name", help="name of notebok (.ipynb) to convert to script (.py)")
+    return parser.parse_args() 
+
+
+def main():
+    args = parse_args()
+    convert(args.notebook_name)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/setup.py b/setup.py
index adb2b59..0d69e82 100644
--- a/setup.py
+++ b/setup.py
@@ -27,7 +27,7 @@ def get_version(short=False):
       author='Will Handley',
       author_email='wh260@cam.ac.uk',
       url='https://github.com/williamjameshandley/py2nb',
-      scripts=['py2nb'],
+      scripts=['py2nb', 'nb2py'],
       install_requires=['nbformat'],
       include_package_data=True,
       license='GPL',